(Tcl) Working with PEM Encrypted Private Keys

Demonstrates how to load and save PEM encrypted private keys.

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load ./chilkat.dll

# Starting in v9.5.0.49, all Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
set chilkatGlob [new_CkGlobal]

set success [CkGlobal_UnlockBundle $chilkatGlob "Anything for 30-day trial."]
if {$success != 1} then {
    puts [CkGlobal_lastErrorText $chilkatGlob]
    delete_CkGlobal $chilkatGlob
    exit
}

set pem [new_CkPem]

set pemPassword "secret"

# To load a PEM file containing encrypted private keys, simply
# provide the password.
set success [CkPem_LoadPemFile $pem "/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem" $pemPassword]
if {$success != 1} then {
    puts [CkPem_lastErrorText $pem]
    delete_CkGlobal $chilkatGlob
    delete_CkPem $pem
    exit
}

set fac [new_CkFileAccess]

set pemText [CkFileAccess_readEntireTextFile $fac "/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem" $pemPassword]

# To load a PEM from a string, call LoadPem instead of LoadPemFile:
set success [CkPem_LoadPem $pem $pemText]
if {$success != 1} then {
    puts [CkPem_lastErrorText $pem]
    delete_CkGlobal $chilkatGlob
    delete_CkPem $pem
    delete_CkFileAccess $fac
    exit
}

# A few notes:
# The PEM may contain both private keys and certificates (or anything else).
# The password is utilized for whatever content in the PEM is encrypted.  
# It is OK to have both encrypted and non-encrypted content within a given PEM.

# PEM private keys can be encrypted in different formats.  The LoadPem and LoadPemFile
# methods automatically handle the different formats.
# One format is PKCS8 and is indicated by this delimiter within the PEM:

# -----BEGIN ENCRYPTED PRIVATE KEY-----
# MIICoTAbBgkqhkiG9w0BBQMwDgQIfdD0zv24lgkCAggABIICgE0PdHJmRbNs6cBX
# ...

# Another format, we'll call "passphrase" looks like this in the PEM:
# -----BEGIN RSA PRIVATE KEY-----
# Proc-Type: 4,ENCRYPTED
# DEK-Info: DES-EDE3-CBC,A4215544D11C5D0C
# 
# paqy9XRexcSjurHfG0xhCaUD0HrvIdhuC0CbRxxxeMlkLaV6+uT80rBxt2AaibWG
# ...

# Show the bit length of each private key:

set numPrivateKeys [CkPem_get_NumPrivateKeys $pem]
if {$numPrivateKeys == 0} then {
    puts "Error: Expected the PEM to contain private keys."
    delete_CkGlobal $chilkatGlob
    delete_CkPem $pem
    delete_CkFileAccess $fac
    exit
}

for {set i 1} {$i <= $numPrivateKeys} {incr i} {
    # privKey is a CkPrivateKey
    set privKey [CkPem_GetPrivateKey $pem [expr $i - 1]]
    puts "$i: [CkPrivateKey_get_BitLength $privKey] bits"
    delete_CkPrivateKey $privKey

}

delete_CkGlobal $chilkatGlob
delete_CkPem $pem
delete_CkFileAccess $fac